Lecture Summaries

Thursday, December 4, 2008

LECTURE ONE
Mapping Memory in the Brain
Eric R. Kandel, M.D.

Webcast 10:00 a.m.–11:00 a.m. ET & PT

What is mind? A central finding is that mind is a series of processes carried out by the brain. Mind is to the
brain as walking is to legs—but it is infinitely more complex. The brain produces our every emotional,
intellectual, and athletic act. It allows us to acquire new facts and skills and to remember them for as long
as a lifetime.

Mind emerges from brain activity, and specific mental functions are localized to different regions in the brain. Over the past few decades, we have found that memory exists in two major forms, each located in different brain regions. Explicit memory is for people, places, and objects. During the memorization process it requires a region deep in the brain called the hippocampus. We depend on our hippocampus to remember our first day in high school. In contrast, implicit memory serves perceptual and motor skills, such as dancing and swimming. It is distributed over multiple brain regions and circuits. In concert, these two memory systems help make us who we are.

Break
11:00 a.m.–11:30 a.m. ET & PT

Lecture Two
Building Brains: The Molecular Logic of Neural Circuits
Thomas M. Jessell, Ph.D.

Webcast 11:30 a.m.–12:30 p.m. ET & PT

The human brain is the sophisticated product of 500 million years of vertebrate evolution, assembled during just nine months of embryonic development. The functions encoded by its trillion nerve cells direct all human behavior—from the simple movements of everyday life to the daring and inspirational thoughts that sometimes emerge. Yet the brain is a biological organ made from the same building blocks as skin, liver, and lung. How does the brain acquire its remarkable computational power? Answers lie in the details of its construction—the cellular and molecular mechanisms that drive the formation of thousands of neural circuits, each wired for a specific behavior. We'll delve into the developmental programs that control brain wiring to understand the cues that trigger neurons to take the correct shape and connect with appropriate partners. As the genetic blueprint for brain wiring unfolds, early experience validates neural networks by frequent use, sculpting the final pattern of neural connections and thus enabling and constraining our behavior. We'll also explore how understanding neural circuit assembly suggests ways of treating the many neurological and psychiatric disorders that result from mistakes in brain wiring.

Friday, December 5, 2007

Lecture Three
Plan of Action: How the Spinal Cord Controls Movement
Thomas M. Jessell, Ph.D.

Webcast 10:00 a.m.–11:00 a.m. ET & PT

Behavior involves movement. Movement drives simple respiratory programs to keep us breathing, as well as displays of emotion—desire, joy, remorse—that project our inner thoughts and moods. Understanding the workings of the neural circuits that control movement gives us a glimpse of how brain wiring and circuit activity control specific behaviors, including one of the more sophisticated aspects of human motor behavior—the movement of our limbs. Consider baseball player Lou Gehrig's remarkable hand-eye coordination as he compiled one of baseball's most impressive hitting streaks, or the purity of cellist Jacqueline du Pré's tone as she played Haydn's Cello Concerto. Yet, both examples also remind us of the fragility of the motor system and its vulnerability to diseases: Gehrig succumbed to amyotrophic lateral sclerosis and du Pré to multiple sclerosis. Neural circuits in the spinal cord direct motor programs with impressive precision, ensuring that the many muscles in a limb are activated in precise temporal order. Sensory feedback systems report on the accuracy of motor programs, and signals from the brain permit us to change motor strategies moment by moment to accommodate an ever-changing world.

Break
11:00 a.m.–11:30 a.m. ET & PT

Lecture 4
Memories are Made of This
Eric R. Kandel, M.D.

Webcast 11:30 a.m.–12:30 p.m. ET & PT

Do the brain's two major memory systems—implicit and explicit—have any common features? Can molecular biology, which has enhanced understanding of many other bodily functions, help us understand mental function?

Implicit and explicit memory both have a short-term component lasting minutes (for example, remembering the telephone number you just looked up) and a long-term component that lasts days, weeks, or a lifetime (for example, remembering your mother's birthday). For both memory processes, the conversion from short- to long-term memory generally requires repetition. And in both, long-term memory requires the synthesis of new proteins. Short-term memory is mediated by modifications of existing proteins, leading to temporary changes in the strength of communication between nerve cells. In contrast, long-term memory involves alterations of gene expression, synthesis of new proteins, and growth of new synaptic connections. It is the growth of synaptic connections—they may be forming in your brain as you read this—that produces enduring long-term memory. Insights into the molecular biology of memory storage have led to an improved understanding of memory disorders produced by brain diseases—and the promise of improved treatments.

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